把多个 PDF 按顺序合并成一个文件。可调每个文件的先后顺序，全部在浏览器本地完成，不上传。Merge multiple PDFs into one, in your chosen order. Everything runs locally in your browser — nothing is uploaded.
加密（带打开密码）或损坏的 PDF 无法读取合并，请先解除密码。合并只拼接页面，不会压缩体积。Password-protected or damaged PDFs cannot be read; remove the password first. Merging only concatenates pages and does not compress the result.